1. Field of the Invention
The invention relates to a circuit configurationfor detecting the steering lock angle of rear wheels of a motor vehicle which are steered with the aid of a drive and an adjusting piston, including a potentiometer for detecting the displacement of the adjusting piston.
2. Description of the Related Art
German Published, Non-Prosecuted Application DE-OS 39 08 164, corresponding to U.S. Pat. No. 4,953,650, describes a control system for the rear wheel steering of a motor vehicle, in which a drive motor drives an adjusting piston that is mechanically coupled to the rear wheels and serves to steer the rear wheels. A potentiometer is used to detect the displacement of the adjusting piston. The command value for the steering lock angle of the rear wheels depends on the steering lock angle of the front wheels, taking vehicle speed into account. Steering of the rear wheels takes place only whenever the signals of sensors used to detect the steering lock angle of the front wheels and of the steering wheel, and sensors used for detecting the vehicle speed, substantially match one another. Several pieces of information from sensors must be evaluated and compared with one another.
However, if the rear wheels are steered, it is important to detect the steering lock angle quickly and without error, because otherwise the situation may become critical in terms of safety. Nevertheless, it has been found that the known control system does not detect the steering lock angle of the rear wheels fast enough.
It is accordingly an object of the invention to provide a circuit configuration for detecting the steering lock angle of the rear wheels of a motor vehicle, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and which detects the steering lock angle of the steered rear wheels quickly and without error.